1，内容是字符串

String json = JSON. toJSONString(list);

结果:["111" ,“222”]

2,内容是时间

SerializeConfig config = new SerializeConfig();
config. put(Date.class, new SimpleDateFormatSerializer("yyyy-MM-dd HH:mm:ss"));
String json = JSON. toJSONString(list, config);
System. out. println(json);

结果：["2022-11-05 11:23:22" ," 2022-11-05 11 :23:22"]

3，内容是对象

List students = new ArrayList<>();

String json = JSON.toJSONString(students);

结果：【{111}，{222}】